Using of Microbial Bio-Surfactants (Rhamnolipid) in Heavy Metals Removal from Contaminated Water

The problem of heavy metals contamination is a global issue and the challenge is to develop methods to remove heavy metals from soil and water. Recently, technologies using microorganisms and microbial products to remove metals have been successfully applied to waste water streams such as sewage sludge, and industrial effluents. The anionic bio-surfactants such as Rhamnolipids that are produced by the bacterium of Pseudomonas species has been used effectively for environmental applications, such as heavy-metal cleanup. The aim of this study is to investigate the ability of Rhamnolipid (bio-surfactants) to remove or reducing heavy metals (Cd^2+, Pb, Ni^2+, Ba, Zn and Sr). Different concentrations (20, 40, 80 ppm) of Rhamnolipid were tested to evaluate its efficiency heavy metals removal. The results showed that, 80 ppm of bio-surfactants reduced up to 53, 62, and 56% of Cd^2+, Pb and Ni^2+ respectively. while were 28, 20 and 7% for Ba, Zn and Sr at the same concentration level. Rhamnolipid could be used successfully as bio-surfactants of several heavy metals from contaminated water in 80 ppm concentration.